A study by the University of Otago comparing different types of nutrition labels found colour-coded “traffic light” labels were better received by people than star ratings or daily intake guides.
They say this raises questions about the introduction of food star ratings on both sides of the Tasman.
Prime Minister John Key announced last week that New Zealand would join Australia in adopting a voluntary regime.
Under the system, foods will be given a rating between half a star and five stars, based on how healthy they are.
But a University of Otago study led by Ninya Maubach suggests seeing stars isn’t as helpful as colour-coded labels.
“Most people can identify healthy products with either the stars or traffic light labels,” she said on Monday.
“However a traffic light label appears much more likely to help people distinguish less healthy choices.”
Kiwi doctors, retailers and a consumer advocacy group have backed the new system, but Dr Maubach says New Zealand should find a solution that works.
“If we want to use labels to reduce obesity, we need a label that promotes quick identification of unhealthy products,” she said.
Dr Maubach said Australian politicians had rejected traffic light labelling even though research supports its effectiveness.
And unlike traffic light labels, there is no peer-reviewed research into the star format.
New Zealand should make labelling mandatory, Dr Maubach said.
“A light-touch regulatory approach that relies on voluntary action is not in consumers’ best interests,” she said.
“A mish-mash of health star ratings, daily intake guides and no labels at all will only exacerbate the confusion we know exists and do little to promote healthier food choices.”